This invention relates to a device for validating valuable papers, in particular, of the type capable of discriminating authenticity of bills with high accuracy and also preventing unauthorized extraction of a bill out of the device.
As shown in FIGS. 25 and 26, a typical prior art bill validating device comprises a casement 71 having an inlet 78 and an outlet 79, a conveyer device 72 for transporting a bill 80 inserted from inlet 78 to outlet 79, a sensor 73 for detecting a physical property such as an optical or magnetic feature of bill 80 transported by conveyer device 72 to produce a detection signal, and a control device 74 for determining whether bill 80 is genuine or not in view of detection signal from sensor 73 to control operation of convey device 72. Casement 71 comprises a lower shell 76 and an upper shell 77 rotatably attached to lower shell 76. Conveyer device 72 comprises a motor 91, a drive gear 92 mounted on an output shaft of motor 91, a first gear 93 in engagement with drive gear 92, a second gear 94 meshed with first gear 93, a main drive pulley 95 driven by second gear 94, and a belt 97 wound around main drive pulley 95 and a plurality of follower pulleys 96 for transporting bill 80 along a guide passageway 70. Pinch rollers 83 are disposed opposite to each of main drive and follower pulleys 95 and 96 to urge bill 80 toward pulleys 95 and 96. Although not shown, but motor 91 comprises a rotary encoder for producing pulse signals generated in synchronization with rotation of motor 91, and a pulse sensor detects and forwards the pulse signals to control device 74. Sensor 73 includes a magnetic sensor such as magnetic head for detecting magnetic pattern by a ferrous element in ink printed on bill 80 or a photo-coupler for detecting light reflected on or penetrating through bill 80. Control device 74 controls operation of conveyer device 72 to transport and discharge bill 80 considered genuine through outlet 79, and stow it into a storage device or stacker mounted below bill validating device. When control device 73 considers bill 80 not to be genuine, it makes conveyer device 72 to drive in the adverse direction to return bill 80 to inlet 78.
As shown in FIG. 25, the bill validating device comprises an anti-pull back device for preventing improper extraction of bill 80 by means of a pull or extraction tool such as a string or tape connected to bill 80 transported toward stacker. Such anti-pull back devices are shown in for example the following Patent Documents 1 and 2. As illustrated in FIG. 25, the anti-pull back device comprises a winder 90 rotatably mounted on a lower shell 76 on guide passageway 70, and a drive motor not shown for rotating winder 90 which has an axial slit 98 for passing therethrough bill 80 transported along guide passageway 70. Control device 74 activates drive motor to rotate winder 90 after bill has passed through slit 98 of winder 90 to wind up any pull or extraction tool connected to bill 80 around winder 90 for prevention of improper bill extraction.
However, such an anti-pull back device is disadvantageous because it has to be separately assembled and then mounted in the bill validating device in addition to conveyer device 72, thereby leading to increase in number of involved parts, rise in cost for manufacture and heavier unit of the device as well as longer passageway of bill and larger size of the device. Also, in the prior art bill validating device shown in FIGS. 25 and 26, when control device 74 cannot correctly detect moving genuine bill 80 for example because of malfunction of sensor 73, the device inconveniently has to return bill 80 to inlet 78 once by adverse rotation of conveyer device 72, and then again transport it in the forward direction for reexamination of bill's physical property through sensor 73. This undesirably extends the examination time of bill 80, and also there is a risk that a user may accidentally pull out bill 80 returned to inlet 78 before resending bill 80 inward.
A bill validator exhibited in the following Patent Document 3, has a carrier which comprises drive rollers rotatably mounted in a case, a drive device for rotating drive rollers and a plurality of pinch rollers for resiliently urging bill toward drive rollers. In this bill validator, when a bill is inserted into an inlet, a motor is driven to rotate pinch and drive rollers so that bill is sandwiched and transported between pinch and drive rollers along an arcuate passageway curved at an angle of approximately 90 degrees in case. A magnetic field generator attached along bill passageway produces an AC magnetic field in passageway so that a magnetic sensor can detect change in magnetic field upon passage of bill therethrough. This can eliminate a mechanism for urging bill toward magnetic sensor to exactly detect magnetic property of bill, and therefore, the device can fully validate even worn-out bills.
[Patent Document 1] Japanese Patent Disclosure No. 9-190559,
[Patent Document 2] Japanese Patent Disclosure No. 11-31250 and
[Patent Document 3] U.S. Pat. No. 5,495,929.
By the way, the devices shown in Japanese Patent Disclosure No. 9-190559 and Japanese Patent Disclosure No. 11-31250 unfavorably require a longer bill passageway for transporting bill and increased number of involved parts because they must transport a bill along linear bill passageway by means of convey belts and incorporate additional anti-pull back device on the way of bill passageway which requires separate validation and anti-pull back areas. In particular, when rotation of a conveyer motor is converted into linear motion by means of conveyer belts, the devices undesirably incur energy conversion loss from electric to kinetic energy. In another aspect, used conveyer belts might give rise to longitudinal elongation due to their own elasticity and inherent structure of spanning conveyer belts between pulleys and winding them around pulleys. Elongation of conveyer belts in contact to bill tends to at least partly reduce the grasping force of bill so as to cause jamming of bill on the way of transportation, fail transportation or hinder smooth transportation of bill. Unlike these, bill validating device shown in U.S. Pat. No. 5,495,929 cannot prevent unauthorized extraction of bill from inside of the device since it has a simplified bill passageway without anti-pull back device.
Accordingly, an object of the present invention is to provide a device for validating valuable papers which has a fused mechanism of conveying and anti-pull back functions while the device can be made in smaller size and lighter weight with less number of parts involved.
Another object of the present invention is to provide a device for validating valuable papers which comprises a rotator arrangement for producing a large grasping force of a bill during its transportation to reliably prevent jamming of bill without conveyer belts.